How Six Americans Changed Their Minds About Global Warming

he Rev. Richard Cizik used to believe climate change was a myth. The science had to be rigged, he thought; those who believed in it were just tree-huggers. But in 2002, a friend convinced Mr. Cizik to go to a conference about climate change, and there, he said, “the scales came off my eyes.”

Nearly 70 percent of Americans now say that climate change is caused mainly by human activity, the highest percentage since Gallup began tracking it two decades ago. The number of Americans who say they worry “a great deal” about climate change has risen by about 20 percentage points.

But people don’t change their minds easily about controversial issues. So what is behind this trend?

Anthony Leiserowitz, the director of the Yale Program on Climate Change Communication, said Americans’ opinions about global warming have fluctuated over the years, shifting along with partisan fissures, extreme weather events and messages from political and religious figures. But the overall upward trend in opinion, he said, was strongly tied to the fact that more people are beginning to relate to climate change as a personal issue.

There are certainly many Americans who remain undecided or doubtful. Toby Wilder, a salesman from Seattle, said he found it hard to imagine that human-caused climate change was anything but a hoax propagated by elites who fly private jets. “If they are wasting more fuel in a month than I do in my lifetime, then how can I believe it?” he asked.

Greg Sandmeyer, a social studies teacher at Timberline High School in Boise, Idaho, is also unconvinced. “It’s one thing to say it’s happening, but it’s another to make laws that will affect me,” he said.

But the broader shift in public opinion, however gradual, has moved toward acceptance of human-caused global warming. In order to learn more about the attitudes that are fueling this change, we spoke with dozens of people. Here are six of their stories.